/*++
 "@(#) NEC isr.c 1.1 95/03/22 21:23:29"

Copyright (c) 1995  NEC Corporation.
Copyright (c) 1991  Microsoft Corporation

Module Name:

    isr.c

Abstract:

    This module contains code for the interrupt service routine
    for the SoundBlaster device driver.

Environment:

    Kernel mode

Revision History:

--*/

#include "sound.h"

//
// Function prototype
//

BOOLEAN
SoundFlushDMA(
    IN    PWAVE_INFO WaveInfo
);

BOOLEAN
SoundMapDMA(
    IN    PWAVE_INFO WaveInfo
);

//
// Driver ISR
//
// When we get here, we acknowledge the interrupt from the
// DSP and simply let the defered processing routine take over
// to complete the task.
//

#if DBG
ULONG sndBogusInterrupts = 0;
#endif // DBG


#define FlushTimeMax	20
LARGE_INTEGER	FlushTime[FlushTimeMax][3];
INT				FlushTimeCount = 0;


BOOLEAN
SoundISR(
    IN    PKINTERRUPT pInterrupt,
    IN    PVOID Context
)
/*++

Routine Description:

    Interrupt service routine for the soundblaster card.

Arguments:

    pInterrupt - our interrupt	   
    Contest - Pointer to our global device info


Return Value:

    TRUE if we handled the interrupt

--*/
{
    PGLOBAL_DEVICE_INFO pGDI;
    BOOLEAN Result;
    UCHAR   oldval;		//  
    
    pGDI = (PGLOBAL_DEVICE_INFO)Context;
    ASSERT(pGDI->Key == GDI_KEY);

     
//	dprintf1(( "I-1" ));
    dprintf5(("<"));

    //
    // Acknowledge the interrupt
    //

    HwInterruptAcknowledge(&pGDI->Hw);	 // Interrupt pin inactive

  	if( pGDI->WaveInfo.Direction ){
		if( pGDI->WaveInfo.MapOn ){
			SoundFlushDMA( &pGDI->WaveInfo );
			SoundMapDMA( &pGDI->WaveInfo );
		}
	}

    //
    // See who the interrupt is for and request the
    // appropriate deferred routine
    //

    Result = TRUE;

    //
    // It is valid to test DMABusy because it is set ON before we start
    // interrupts

    if (pGDI->WaveInfo.DMABusy) {
        
        dprintf5((pGDI->WaveInfo.Direction ? "o" : "i"));

        //
        // Check to see if we're overrunning, don't queue a Dpc if
        // we are.
        //

        if (!pGDI->WaveInfo.DpcQueued) {

            pGDI->WaveInfo.DpcQueued = TRUE;

            // ASSERTMSG("Overrun count not zeroed by Dpc routine",
            //          pGDI->WaveInfo.Overrun == 0);

            IoRequestDpc(pGDI->WaveInfo.DeviceObject,
                         NULL,
                         NULL);

        } else {
            //
            // Overrun !
            //
            
            if (pGDI->WaveInfo.Overrun == 0) {
                dprintf2(("Wave overrun"));
            }
            
            pGDI->WaveInfo.Overrun++;
        
        }

    } else {
#if DBG
        // We only get 10 valid interrupts when we test the interrupt
        // for validity in init.c.  If we get lots more here there
        // may be a problem.

        sndBogusInterrupts++;
        if ((sndBogusInterrupts % 20) == 0) {
            dprintf(("%u bogus interrupts so far", sndBogusInterrupts - 10));
        }
#endif // DBG

        //
        // Set the return value to FALSE to say we didn't
        // handle the interrupt.
        //

        Result = FALSE;
    }

    dprintf5((">"));
	
    return Result;
}